1. Field of the Invention
The present invention relates to a slide apparatus and mobile handset having a sliding object that slides along a predetermined slide path, wherein the sliding object is stably held at two points on the slide path. More particularly, the present invention relates to a lock mechanism for realizing a function like the above.
2. Description of the Related Art
FIG. 1 illustrates a schematic configuration of a mobile phone or similar mobile device provided with a camera unit 12 housed in a chassis 13, as well as a cover 11 (the sliding object herein) that selectively covers the lens unit of the camera unit 12 in order to protect the lens unit. When the camera of the mobile device is not in use, the camera unit 12 is closed and covered by the cover 11, as shown in FIG. 1A. The cover 11 is slidably supported by the chassis 13, such that when the user applies an external force F1 to the cover 11, the cover 11 is moved to the open position. As shown in FIG. 1B, when the cover 11 is opened by sliding, the camera unit 12 appears and taking photographs becomes possible.
In order to prevent the cover 11 from accidentally sliding, a control mechanism is normally installed whereby the open position and the close position of the cover 11 are held in place by some means like the following. FIGS. 2A and 2B illustrate an exemplary configuration of a mobile device having a position control mechanism of the related art, the mechanism herein providing a click response in addition to position control. The position control mechanism shown in FIGS. 2A and 2B includes a spherical part 23 that is pressed against the inner wall of the cover 11 in both the open position and the close position as a result of the press force F3 of a push spring 24. Provided on the inner wall of the cover 11 are recessed portions 21 and 22, into which the spherical part 23 enters during the close position and the open position, respectively. Click response is produced as a result of the spherical part 23 entering the recessed portions 21 and 22, while additionally, the above functions as a lock configuration whereby the cover 11 is not moved accidently. In addition to the above, a lens cover configuration provided with an independent click mechanism has also been proposed (see Japanese Unexamined Patent Application Publication No. 2007-65443).
However, in the mobile device shown in FIGS. 2A and 2B, the click function occurs only at the ends of a slide stroke, and cover position control at a position midway along the slide stroke has been difficult to implement.
FIGS. 3A and 3B illustrate the configuration of a mobile device of the related art having improved usability. The mobile device shown in FIGS. 3A and 3B includes a spring (not shown) that generates a closing force in a particular direction so as to keep the cover 11 in the closed state. As a result of the closing force F5 generated by the spring, the cover position is controlled such that the cover 11 is not accidently slid from the close position. When the user slides the cover 11 by applying an external force F4 sufficient to overcome the closing force F5 of the spring, the spring is compressed. The spring becomes maximally compressed in the open position and thereby stores a force F6. At this point, when the external force F4 is removed, the cover automatically returns from the open position to the close position. In so doing, usability is improved. However, when usage of the camera unit 12 is considered with respect to the mobile device shown in FIGS. 3A and 3B, it is desirable to install a lock mechanism for the cover 11 when in the open position.
FIGS. 4A, 4B, and 4C illustrate a mobile device wherein a lock mechanism 40 for the cover 11 has been provided with respect to the mobile device shown in FIGS. 3A and 3B. When the user moves the cover 11 to the open position by applying an external force F7, the lock mechanism 40 engages a protruding portion 11a of the cover 11 such that the cover 11 remains in the open position even when the user ceases to apply the external force F7. When the user subsequently rotates the lock mechanism 40 about an axis 41 by applying an external force F10 to the lock mechanism 40, the cover 11 is disengaged from the tip 42 of the lock mechanism 40 and is automatically returned to the initial position by means of the closing force F11 of the spring.